Endocrine — Systems, Processes & Functions

Question 1

What is the endocrine system?

Answer 1

A system of glands that secrete hormones into the blood to regulate body functions.

Question 2

How do endocrine and nervous systems differ?

Answer 2

Nervous → fast, short-lived, electrical impulses. Endocrine → slower, long-lasting, chemical messengers.

Question 3

What hormone does the anterior pituitary secrete to regulate reproduction?

Answer 3

FSH & LH.

Question 4

What hormone does the posterior pituitary secrete to regulate water balance?

Answer 4

Antidiuretic Hormone (ADH)

Question 5

Role of ADH? How?

Answer 5

Regulates water levels/ balance within the body. Through triggering the kidney to reabsorb more water from the urine when water levels within the body are low. This controls urine concentration and helps the body avoid dehydration and maintain hydration levels (homeostasis).

Question 6

When does the posterior pituitary gland secrete ADH?

Answer 6

High blood solute concentration = low levels of water within the body (detected by osmoregulatory cells in the hypothalamus).

Question 7

Which hormone does the thyroid produce?

Answer 7

Thyroxin.

Question 8

Role of thyroxin?

Answer 8

Increases basal metabolic rate, growth, development.

Question 9

What disorder results from iodine deficiency?

Answer 9

Goitre (swollen thyroid).

Question 10

What disorder results from too little thyroxin in childhood? (Congenital Hypothyroidism)

Answer 10

Cretinism (stunted growth, mental delay).

Question 11

Which hormones are secreted by the pancreas?

Answer 11

Insulin (β-cells), Glucagon (α-cells).

Question 12

Role of insulin?

Answer 12

Lowers blood glucose levels to restore homeostasis, promotes:

Glucose ~ Fats
Glucose ~ Glycogen
Glucose uptake in cellular respiration

Question 13

Role of glucagon?

Answer 13

Raises blood glucose, stimulates the breakdown:
Glycogen ~ (breakdown) ~ Glucose

Question 14

What causes Type I diabetes?

Answer 14

Autoimmune destruction of β-cells → no/ insufficient insulin production.

Question 15

What characterizes Type II diabetes?

Answer 15

Not enough insulin produced by the B-cells; Insulin resistance at target cells.

Question 16

Complications of untreated diabetes?

Answer 16

Kidney damage, blindness, poor wound healing.

Question 17

Which hormone is secreted by the adrenal medulla?

Answer 17

Adrenaline (Epinephrine)

Question 18

Role of adrenaline?

Answer 18

Prepares body for fight/flight (↑ heart rate, ↑ glucose, pupil dilation).

Question 19

Which hormone is secreted by the adrenal cortex?

Answer 19

Cortisol.

Question 20

Role of cortisol?

Answer 20

Stress hormone; regulates metabolism, suppresses immune system. (Immunosuppressant)

Question 21

Which hormone stimulates follicle growth in ovaries?

Answer 21

FSH.

Question 22

Which hormone triggers ovulation?

Answer 22

LH.

Question 23

Which hormone stimulates secondary sexual characteristics in females?

Answer 23

Oestrogen.

Question 24

Which hormone maintains pregnancy?

Answer 24

Progesterone.

Question 25

Which hormone stimulates secondary sexual characteristics in males?

Answer 25

Testosterone.

Question 26

What is negative feedback?

Answer 26

A mechanism where a change triggers responses that counteract it (restore balance).

Question 27

Give one example of negative feedback in the endocrine system.

Answer 27

Thyroxin: ↑ thyroxin inhibits TSH from pituitary → prevents overproduction.

Question 28

How is the regulation of blood sugar levels within the body an example of a negative feedback mechanism?

Answer 28

Blood glucose: ↑ glucose triggers insulin → lowers glucose. ↓ glucose triggers glucagon → raises glucose.

Question 29

Why might athletes abuse EPO?

Answer 29

Increases red blood cells → more oxygen delivery → better endurance.

Question 30

Why might athletes abuse anabolic steroids?

Answer 30

Increase muscle mass and strength.

Question 31

Give one health risk of anabolic steroid abuse.

Answer 31

Infertility, liver damage, cardiovascular disease.

Question 32

(2025 May) Why does ADH secretion increase after intense exercise?

Answer 32

Exercise causes water loss (sweat) → ↑ blood solute concentration → hypothalamus triggers ADH release.

Question 33

(2024 May) Why is iodine added to table salt in many countries?

Answer 33

Prevents iodine deficiency → prevents goitre/cretinism.

Question 34

(2023 Nov) Explain why untreated diabetes can lead to constant fatigue.

Answer 34

Glucose cannot enter cells for respiration → low ATP production → fatigue.

Question 35

(2022 Nov) Why is the pituitary gland called the “master gland”?

Answer 35

It secretes hormones that regulate other endocrine glands (thyroid, gonads, adrenal).

Question 36

Describe the term Basal Metabolic Rate (BMR), stating what it is.

Answer 36

The energy required for an individuals involuntary movement in a resting position.